Insulated wall structure for containers and method of forming



March 3, 1970 A. F. LOVELAND ETAL INSULATED WALL STRUCTURE FORCONTAINERS AND METHOD OF FORMING 4 sheets-sheet 1 Filed June 20, 1966FIG. 2.

INVENTORS.

ARTHUR F. LOVEL'AND GLENN W. SITLER BY ZJ M ATTORNEY March-3, 1970 A. F.LOVELAND ETAL 3,493,237v

INSULATED WALL STRUCTURE FOR CONTAINERS AND METHOD OF" FORMING FiledJune 20, 1966 I 4 Sheets-Sheet 2 FIG. 3.

'' March 3, 1970 A. F. LCVELAND ETAL 3, 35 73 INSULATED WALL STRUCTUREFOR CONTAINERS AND METHOD OF FORMING Filed June 20, 1966 4 Sheets-Sheet5 I March 1970 A. F. LOVELAND ETAL 3,493,237

INSULATED WALL STRUCTURE FOR CONTAINERS AND METHOD OF FORMING Filed June20, 1966 4 Sheets-Sheet 4 FIG. 5.

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United States Patent 3,498,237 INSULATED WALL STRUCTURE FOR CONTAIN- ERSAND METHOD OF FORMING Arthur F. Loveland, St. Charles, and Glenn W.Sitler, St. Louis, Mo., assignors to ACE Industries, Incorporated, NewYork, N.Y., a corporation of New Jersey Filed June 20, 1966, Ser. No.558,650 Int. Cl. 361d 17/18, 17/08, 17/12 US. Cl. 105-355 8 ClaimsABSTRACT OF THE DISCLOSURE An in-place foam insulated wall for acontainer structure, such as a railway car, in which a pair of spaced,generally parallel sheets are secured adjacent the outer wall of acontainer and form an enclosure in which the expanding foam material ispoured. A slightly flexible outer sheet is spaced from the outer walland is lightly fastened to have a lesser resistance to flexure andbulging from the internal pressure of the foam material. The outer sheettends to bulge or bow outwardly into the space adjacent the outer wallupon expansion .of the foam material.

Heretofore, in containers such as railway box cars, insulated wallstructures have been formed in-place within the box car employing asuitable rigid plastic foam of a cellular structure, such as apolyurethane, polystyrene, epoxy, silicone, phenolic, or syntactic foammaterial. For example, a polyurethane foam system employs severalingredients which are mixed together and then applied to an enclosurewith a subsequent expansion to fill the enclosure. The followingingredients are normally mixed: (1) a polyether or polyester base, (2)an isocyanate base employed as an activator, (3) a fluorocarbon blowingagent, and (4) a catalyst. As the foam material expands into theenclosure to form a rigid cellular structure, the expanding materialexerts a pressure against the framework forming the enclosure and inmany instances, particularly if the adjacent sides or sheets forming theenclosure are not of a substantial rigidity, will tend to bulge orwrinkle the adjacent sheets. Such sheets or sides which buckle orwrinkle present an irregular surface and displeasing appearance whenexposed to view and are undesirable. One method heretofore employed withinner sheets forming the interior exposed wall surface of a railway boxcar has been to provide bracing to reinforce the walls against bucklingwith the bracing being removed after the insulating material is pouredand becomes a rigid cellular structure. The installation and subsequentremoval or bracing is costly as well as time consuming.

This invention comprises the use of a pair of spaced, I

generally parallel sheets secured adjacent the outer wall of a containerand forming an enclosure into which an expanding foam material may bepoured, the outer sheet being spaced from the outer wall and having aless r resistance to flexure and bulging from the internal pressure ofthe expanding foam material than the inner sheet.

The outer sheet is at least slightly flexible and will tend to bow orbulge outwardly into the space formed between the outer sheet and theouter wall upon the expansion of any foam insulation material thereby tomaintain the exposed inner sheet and the exposed outer wall with aminimum of surface irregularities. As the space between the outer walland the outer sheet remains a void, only a minimum of foam material isemployed.

It is an object of this invention to provide an insulated wall structurewith an expanding foam material which is formed in-place within acontainer, such as a railway box car, highway trailer, or detachableportable container.

Another object of this invention is the provision of such an insulatedwall structure in which a minimum of bracing or shoring is required inorder to form the wall structure and a minimum of foam material isemployed.

A further object of this invention is the provision of such an insulatedwall structure in which the exposed surfaces of the wall structure havea minimum of surface irregularities and present a pleasing appearance.

An additional object of this invention is the provision of a method toform such an insulated wall structure from an expanding foam material inwhich a minimum of shoring or bracing is required.

The invention accordingly comprises the constructions hereinafterdescribed, the scope of the invention being indicated in the followingclaims.

In the accompanying drawings, in which several of various possibleembodiments of the invention are illustrated,

FIGURE 1 is a side elevation of a railway box car with which the presentinvention is commonly employed;

FIGURE 2 is a transverse section of the railway box car shown in FIGURE1 and illustrating the railway car before the expanding foam material isapplied;

FIGURE 3 is a partial side elevation with certain parts broken away andillustrating the foam material for the roof structure;

FIGURE 4 is a transverse section of the upper wall structure or roofstructure employing the present invention with an insulating material ofan expanding foam material between a pair of sheets;

FIGURE 5 is an enlarged fragment of FIGURE 4 illustrating the bulging orbowing of the outer sheet and the means permitting such bulging;

FIGURE 6 is a schematic view in plan illustrating the general methodemployed in applying the foam material to the roof structure;

FIGURE 7 is a transverse section of the side wall structure employingthe present invention with an insulating material of an expanding foammaterial in the cavity or space provided between a pair of sheets; and

FIGURE 8 is a longitudinal sectional view of the side wall structureillustrating the space between the pair of sheets to receive theexpanding foam material and the means to permit a bulging of the outersheet.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawmgs.

Referring to the drawings, a railway box car is indicated generally at10 in FIGURES 1 and 2 and includes side wall structures 12, end wallstructures 14, an upper wall or roof structure 16, and a lower or bottomwall structure 18. The present invention may be employed with any wallstructure although only the side 'wall structure and the upper wallstructure have been illustrated in the drawings as employing the presentinvention. While a railway box car 10 is illustrated in the drawings, itis to be understood that the present invention is applicable to otherstructures, such as highway trailers or detachable containers.

It is desirable in many instances to provide an insulated container tomaintain a generally constant temperature within the container and tominimize heat transfer between opposite sides of the wall structuresforming the container. Expandable foam materials, such as polyurethanes,polystyrenes, epoxies, silicones, phenolics, and synthetics, have beenfound to be satisfactory for the insulating material. Upon expansion ofthe foam material, pressure is generated and acts against the confiningsurfaces tending to press the surfaces outwardly. Especially when arelatively thin sheet is exposed interiorly of the container, wrinklesor bulges may develop which present a displeasing appearance. While suchWrinkles or bulges can be controlled when a prefabricated or preformedinsulated panel is made, it is very diflicult to control'when theinsulated wall structure is formed in place with sheets of a smallthickness.

Referring particularly to FIGURES 3-5, the upper wall structure or roofstructure 16 is illustrated. Roof structure 16 comprises a side plate 20of a W configuration in cross section, and a roof 22 extending over sideplate 20 and secured thereto, such as by welding or riveting. Extendingbetween side plates 20 is a ceiling panel or sheet 24 exposed to theinterior of box car and formed of plywood around one-half /2) inch inthickness. A side panel or sheet 26 of one-half /2) inch plywood formsan interior side lining of box car 10 and is spaced from an outer liningor wall 28 formed of sheet metal around one tenth (.10) inch inthickness. A longitudinally extending wooden strip 30 is secured to aninterior side sheet or lining 26 and sheet 24 is nailed between oppositestrips 30. An intermediate wooden filler strip or spacer 34 is securedto sheet 24 and extends longitudinally of railway car 10. Transverselyextending wooden carlines 34 are spaced along the length of car 10 andare secured to spacer 34. An outer sheet generally indicated 37 isformed of a pair of sheet portions or sections 36 being of a thicknessof around one fourth A) inch and slightly flexible are secured overspacer 34 and carlines 35. To secure sheet sections 36 to spacer 34,nails 38 are positioned along the marginal edge portions of sections 36but are not nailed tightly against sections 36. Thus, the heads of nails38 are slightly spaced from the adjacent surfaces of sections 36 whenthe sections 36 are initially positioned. Sheet sections 36 are alsolightly fastened to carlines 35 with suitable fasteners such as nails.The fasteners of sections 36 to carlines 35 are easily pulled loose whenpressure is formed by the foam material to permit bowing of sheet 37.Nails 38 securing sections 36 to spacer 34 do not pull loose, however,as sections 36 tend to tear around nails 38 when pressure is exertedagainst the inner surface of sections 36.

Referring particularly to FIGURE 6, apparatus is indicated at 40adjacent each end of car 10 to mix the ingredients of the foam material.Dispensing tubes 42 lead from each apparatus '40 within the space formedbetween sheets 24 and 37 and through suitable openings 46 in carlines35. As the foam material is dispensed from the ends of tube 42, thetubes are withdrawn slowly through the openings in carlines 35. The foammaterial after being dispensed from the ends 44 of tubes 42 expands tofill the cavity or space between outer sheet sections 36 and lower sheet24. Outer sheet 37 may be formed of plywood, masonite, or other slightlyflexible material which has a lesser resistance to flexing or bulgingthan sheet 24 since sheet 37 is of a lesser thickness. As nails 38 arein the marginal edge portions of sections 36 closely adjacent the edgesthereof, the bulging of sheet 37 tends to tear or rip the sectionsimmediately adjacent nails 38 thereby permitting sheet 37 to bulge orhow to the shape shown in FIGURES 4 and 5. Sheet 24 has only a minimumof bulging and thereby generally maintains its initial shape. Whilesections 36 how, nails 38 retain sections 36 in position as the sectionsdo not completely tear away from nails 38. However, sections 36 do bowor pop away from carlines 35 under pressure of the expanding foammaterial as sections 36 are only lightly nailed or fastened to carlines35. Thus, sheet sections 36 act as a pressure relief to preventexcessive pressures being exerted against sheet 24. Sheet 37 minimizesthe amount of insulating material employed in roof structure 16 assections 36 are spaced from roof 22 and foam material is not used in thespace formed between sheet 37 and roof 22.

Referring to FIGURES 7 and 8, an insulated side wall structure 12 isillustrated. Side posts 48 of a generally channel shape are spaced alongthe length of outer lining or outer Wall 28 to reinforce the side sheet.Outer wall 28 is formed in a plurality of portions each welded toadjacent side posts 48 as shown in FIGURE 8. As lining 28 is normally ofsheet metal having a thickness of around one-eighth 4;) inch, theexpanding foam material if poured in contact with wall 28 will tend towrinkle or bow wall 28 thereby presenting an unpleasing appearance.Mounted between outer wall 28 and interior sheet 26 is an outer sheetgenerally indicated 49 formed of a pair of sheet sections 50 adapted tobow or bulge when the expanding foam material is positioned betweensheets 26 and 49 thereby preventing or minimizing any bowing of wall 28.

To secure inner sheet 26 and outer sheet 50, a plurality of studs 52 arewelded to the inner face of each channelshaped post 48 and extendthrough suitable openings in wooden posts 54 and wooden spacers 56.Posts 54 are first positioned on studs 52 and the marginal edge portionsof sections 50 are nailed to posts 54, spacer 58 being previouslysecured to a pair of sections 50 by nails 60. Nails 60 are positionedalong the marginal edge portions of sections 50 to permit a slighttearing out with the heads of nails 60 being slightly spaced from theadjacent surface of sections 50. Next, spacers 56 are mounted'on studs52 and nuts 62 are drawn tight to hold posts 54 and spacers 56 insecured position. Inner sheet 26 is then nailed to spacers 56. Theexpanding foam material is applied within the void formed between sheet26 and sections 50 in a manner similar to that illustrated in FIGURE 6for roof structure 16. Suitable openings 64 are provided in spacers 56and 58 to receive a foam dispensing tube and the tube is withdrawnslowly as the space is filled between sheet 26 and 49. In most instancesside wall structures 12 are insulated first and then roof structure 16is insulated. It is noted that a passage is provided between the voidspace in roof structure 16 and thevoid space in side wall structures 12.Thus, an overflow of foam material from side wall structures 12 intoroof structure 16 may occure when side wall structures 12 are firstpoured. This permits a type of pressure relief for side wall structures12.

Referring to FIGURE 2, the bottom wall or floor structure 18 may beinsulated by the dispensing of foam material in the void space beneaththe floor panel 65. Cross members 66 have openings to receive adispensing tube. Stringers 68 extend longitudinally and a lower sheet 70is secured beneath stringers 68. Sheet 70 is not shown as being flexibleand bowing or bulging when the foam material is applied. However, ifdesired, a floor structure similar to roof structure 16 could beprovided having a flexible outer sheet to bow thereby to prevent bowingof floor panel 65.

From the foregoing, it is to be understood that the present inventionprovides an in-place insulation for a wall structure in a container,such as a railway box car in which a flexible sheet is arranged to actas a pressure relief for expanding foam materal thereby to preventexcessive pressure being applied against an adjacent spaced sheet orwall.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results obtained.

What is claimed is:

1. A method of forming an in-place insulating wall structure for arailway box car comprising the steps of initially securing a pair ofgenerally parallel spaced sheets in place within the box car for formingthe wall structure with the sheets forming an enclosure therebetween,and placing an expanding foam material within the enclosure formedbetween said sheets with said foam material expanding to fill theenclosure and forming a rigid cellular foam insulation between thesheets, one of said sheets being more flexible and less resistant thanthe other sheet to the pressure generated by the expanding foam materialas it fills the space between the sheets with said one sheet tending tobulge and flex outwardly thereby to minimize any pressure generated bythe foam material against the other sheet to maintain the other sheetwith a minimum of surface irregularities.

2. The method as set forth in claim 1 and further comprising the stepsof forming said one sheet of two adjacent sections arranged inedge-to-edge relation, positioning a spacer between the tWo sheets atthe juncture of said adjacent sections, and lightly fastening themarginal edge portions of the two sections to said spacer whereby theexpanding foam material urges the sections away from said spacer topermit bulging of the sections.

3. A method of forming an in-place insulating panel adjacent an outerwall of a container body, comprising the steps of positioning a pair ofgenerally parallel spaced sheets adjacent said outer wall with the outerof said sheets being spaced from the outer wall to form an open spacebetween the outer wall and outer sheet and placing an expanding foammaterial within the open space formed between said sheets with said foammaterial expanding to fill the space between the sheets and forming arigid cellular foam insulation, the outer of said sheets being moreflexible and less resistant than the outer sheet to the pressuregenerated by the expanding foam material as it fills the space betweenthe sheets with said outer sheet tending to bulge and flex into thespace between said outer wall and said outer sheet to relieve anypressure generated by the foam material against said inner sheet therebyto maintain the inner sheet and the outer wall with a minimum of surfaceirregularities.

4. The method as set forth in claim 3 further comprising the steps offorming said outer sheet of two adjacent sections arranged inedge-to-edge relation, positioning a spacer between the two sheets atthe juncture of said adjacent sections, and lightly fastening themarginal edge portions of the two sections to said spacer whereby theexpanding foam material urges the sections away from said spacer topermit bulging of the sections.

5. A framing structure secured within a container body adjacent an outerwall thereof and forming a permanent portion of said container body,said framing structure adapted to receive an expanding foam insulationmaterial therein for forming an in-place insulating panel adjacent saidouter wall, said framing structure comprising an inner sheet forming anexposed interior surface for the container body, an unexposed outersheet spaced outwardly from the inner sheet in generally parallelrelation thereto, means to hold the sheets in generally parallel spacedrelation to form an open space therebetween, said outer sheet beingspaced from the adjacent outer wall of the container body to form aspace therebetween and comprising two adjacent sections arranged inedge-to-edge relation, an intermediate spacer between the two sheets atthe juncture of the adjacent sections, and means lightly fastening themarginal edge portions of the two sections to said intermediate spacerwhereby said sections are adapted to be urged away from saidintermediate spacer when expanding foam material is positioned in thespace between the two sheets, said outer sheet being less resistant tointernal pressure from an expanding foam material than said inner sheetand adapted to bulge outwardly into the space formed between the outersheet and the outer wall upon the expansion of any foam insulationmaterial positioned between the sheets to minimize any excessivepressure applied against the inner sheet from the expanding foammaterial thereby to maintain the exposed inner sheet and the outer wallwith a minimum of surface irregularities.

6. A wall structure for a railway box car comprising an outer wallforming a permanent portion of said container body, a pair of generallyparallel spaced sheets positioned inwardly of said outer wall, means tohold the sheets in generally parallel relation with said outer sheetbeing spaced from the adjacent outer Wall of the container body to forma space therebetween, said outer sheet being less resistant to internalpressure from an expanding foam material than said inner sheet andadapted to bulge outwardly into the space formed between the outer sheetand the outer wall upon the expansion of any foam insulation materialpositioned between the sheets to minimize any excessive pressure appliedagainst the inner sheet from the expanding foam material thereby tomaintain the exposed inner sheet and the outer wall With a minimum ofsurface irregularities, said outer sheet comprising two adjacentsections arranged in edge-to-edge relation, and means adjacent thejuncture of the adjacent sections lightly fastening the marginal edgeportions of the two sections whereby said marginal portions are adaptedto be unfastened and urged outwardly to permit a bulging of the outersheet when expanding foam material is positioned in the space betweenthe two sheets.

7. A wall structure for a railway box car as set forth in claim 6wherein said wall structure is an upper wall structure and said outerwall is a roof, said inner sheet forming a ceiling for the box car andexposed to the interior of the box car, said outer sheet comprising atleast two adjacent sections arranged in edge-to-edge relation, and meansadjacent the juncture of the adjacent sections lightly fastening themarginal edge portions of the two sections whereby said sections areadapted to be unfastened and urged outwardly to permit a bulging of theouter sheet when expanding foam material is positioned in the spacebetween the two sheets.

8. A wall structure for a railway box car as set forth in claim 6wherein said wall structure is a side wall structure and said outer wallis a side lining formed of a sheet metal material having a relativelysmall thickness, said inner sheet forming the inner lining exposed tothe interior of the box car, said outer sheet comprising at least twoadjacent sections arranged in edge-to-edge relation, and means adjacentthe juncture of the adjacent sections lightly fastening the marginaledge portions of the two sections whereby said sections are adapted tobe unfastened and urged outwardly to permit a bulging of the outer sheetwhen expanding foam material is positioned in the space between the twosheets.

References Cited UNITED STATES PATENTS 4/1961 Kloote et a1. 360 4/ 1967Kravskopf 105--360

